A heartbeat measurement device includes a device main body, a heartbeat detection portion, formed integrally with the device main body, which has electrodes that come into contact with a biological surface, and a fixing band, formed in a belt shape, which fixes the device main body and the heartbeat detection portion to a human body. Both ends of the fixing band in a long-side direction are detachably installed on the device main body through an engagement portion constituted by a hook portion and an engaged portion.
